1. Technical Field
The present invention relates to a terminal treatment method and a terminal treatment apparatus of a coaxial cable having an inner conductor and an outer conductor.
2. Background Art
As electric cables having a shielding function, coaxial cables covering an outer peripheral of an inner conductor have been used from the past (for example, see JP-A-2004-171952 and JP-A-2007-66825).
Also, a technique for terminal-treating such coaxial cables, in which an inner conductor in a terminal portion thereof is separated from an outer conductor, has been known (for example, see JP-A-H1-081608). According to this terminal treatment, an outer conductor 1 formed of fine wires is untwisted as shown in FIG. 23 and then the outer conductor 1 is separated from a center conductor 3 by air from an air knife 2 as shown in FIG. 24. Next, the separated outer conductor 1 becomes upright and a bundle of fine wires of the outer conductor 1 is sandwiched and then stretched and twisted by a gripping tool 4 as shown in FIGS. 25A to 25C.
However, there is a case that a coaxial cable, in which an outer conductor disposed on an outer circumference of an inner conductor is intended to be used as a lead like the inner conductor, not as a shielding use, is employed for a wire harness wired in a vehicle, such as an automobile. In a case of such a coaxial cable, the inner conductor in a terminal thereof is separated from the outer conductor and then each of the inner conductor and the outer conductor is connected to a respective connector.
In the coaxial cable used as this application, because the outer conductor does not have a small diameter as in the shielding use, when the outer conductor is untwisted, a sheath and the outer conductor of the coaxial cable chucked are slipped relative to each other, thereby causing insufficient untwisting.
Further, in a case of an outer conductor having a large wire diameter, it is difficult to separate the outer conductor by air of the air knife. In addition, when the separated outer conductor is bundled, if a bundle of wires of the outer conductor is sandwiched and then stretched and twisted, the outer conductor can be damaged or broken and thus deterioration of electrical and mechanical properties is worried.
Accordingly, the present invention has been made keeping in mind the above problems, and an object of the invention is to provide a terminal treatment method and a terminal treatment apparatus for a coaxial cable, in which an outer conductor and an inner conductor can be easily branched from each other.